Gas turbine plant



Feb. 18, 19474. w. TRAUPEL GAS TURBINE PLANT original Filed April 2, 1942 'ATTORNEYS .RessuedFeh 18, 1947 GAS TURBINE .PLANT Walter Traupel, Winterthur, Switzerland, assignor to Sulzer Freres Societe Anonyme, Winterthur, Switzerland Original No. 2,361,887, dated October 31, 1944, Serial No. 437,341, April 2, 1942. Application for reissue November 19,

1945, Serial No.

629,414. In Switzerland June 27, 1941 7 Claims. (Cl. 60-491 The invention relates to a gas turbine plan Whose working medium flows ina circuit from which some of the working medium is taken, and to replace it a make-up quantity is introduced. The rotary compressor supplying the make-up quantity of working medium to the circuit can in principle be driven in two different manners, either by a separate machine, or by being coupled to a gas turbine producing the useful output of .the plant. If` the compressor is driven by a separate machine, for instance by an exhaust gas turbine, this entails the drawback that a balance must be maintained, with the help of regulating devices, between the compressing w power required for the working condition of the lwhole plant and the power of the driving machine, whereby there will be fluctuations in the service in consequence of the inertia of the regulating devices. On the otherV hand, if the compressor is driven by a turbine producing the useful output, or even if the compressor driven by an exhaust gas turbine is coupled to one f the principal machines to balance the output, this entails the drawback that the speed of the compressor is no longer adjustable and therefore the quantity of make-up working medium must be adjusted by throttling in accordance with the working conditions. This throttling, however, causes a sensible loss of power. l

To'avoid the drawbacks mentioned above, it is proposed in accordance with the invention to t the rotary compressor introducing the make-up quantity of working medium into the circuit, witha turbine stage which has adjustable guide wheels-this turbine stage giving power to the rotor and being arranged before the compressor blading-and to couple the compressor to a tur` bine giving the effective output. In this manner it is possible, when the compressor is coupled direct to a gas turbine developing the useful work, for the work which is set free through regulating the replacement quantity by reducing the pressure before the compressor, to be utilised again in the compressor, instead of being destroyed.

Preferably a mechanical coupling is provided between the compressor supplying the additional quantity of working medium and the turbine producing the effective output, in order to be able to maintaina fixed ratio between the'speeds of the two machines.

One exampleof an execution according to the invention is illustrated in a simplified manner in the drawing. Fig. l shows a plan according to the invention; Fig. 2 illustrates a longitudinal section through the compressor of the plant acy2 cordingto the invention delivering the make-up quantity of working material; Fig. 3 shows the arrangement of the blading; Fig. 4 the velocity triangles of the compressor according to Fig. 2, and Fig. 5 is a sectionalview along the line 5-5 of Fig. 2. v

The compressor I delivers working medium which has been drawn in through the pipe 2, this delivery being effected, through thepipe system 3 of a recuperator 4 and the pipe system 5 of a gas heater 6, into the turbine 'I. The working medium after expansion passes from the turbine throughfthe pipe 8 into the recuperator 4, in which it heats the pipe system 3; it then passes into the cooler 9, in which it is cooled by the pipe system III. Through the pipe 2 the working *medium* is nally again led to the compressor I and the circuit begins again.

A part of the working medium is withdrawn from the circuit through pipe I9 and led as combustion air into the combustion space of the gas heater 6. The gases produced in the gas heater iiow through thelplpe II into the exhaust turbine I2, and then through pipe I3 to atmosphere or to' other points of use.

To replace' the quantity of working medium withdrawn from the circuit through pipe I9, fresh working medium, for instance air, is drawn by the compressor I4 from pipe I5 and introduced in a compressed' state through pipe IG-into the cooler 9. 'I'he gas turbine 1 and the exhaust turbine I2 are arranged on one common shaft with the compressors I and I4 and with the electric generator I1 which gives the useful output of the whole plant to the electric system I8. The shaft -runs at a constant speed, corresponding to the 22-25, of which the row 22 acts as a turbine and the rows 23--25 `as compressor. An adjustable row ofv guide blading 26 is iitted before the turbine blading 22,l and a fixed row of guide bladng 21--29 before each of the ccmpressorebladings r2li- 25. Each blade of the row of guide blading 26 is fitted on a shaft 30 which can be adjusted by means'of an arm 3l and a rod 32 according to the quantity of air to be compressed.

Between the space I3 before the adjustable guide blading 26of the turbine stage and the space 34 behind the turbine runner .blading 22, a bypass passage 36 is provided, which can be closed by the valve 35, and through this passage the working medium to be compressed can'be introduced direct from the space 33 to the first guide blading 21 of the compressor.

For the form of blading shown in Fig. 3 for the impeller blading 22-25 and the guide blading 21-29, the now velocities in normal service are given in the diagrams in Fig. 4.

co represents the absolute inlet velocity in the turbine runner blading 22. The blading is formed in such a way that the outlet velocity cifrom the turbine runner blading 22 is equal'to the proper inlet velocity in the successive compressor guide blading 21. 'I'he relative inlet and/or outlet velocities wt and w1 respectively, which determine the form of the turbine blades, correspond to the absolute inlet and outlet velocities co and c1.

In the guide blading 21 the inlet velocity c1 velocities wz and wa respectively, which are dei cisive vfor the blade form and blade adjustment of the compressor runner blading, correspond to the absolute velocities c2 and ca in the guide blading 23. It can be seen that the working medium is' sues from the impeller blading 23 directed in the same way and fic-wing with the same velocity as it entered the guide blading 21. For this reason the proles are the same in all stages, provided that the height f the blading in the successive Iclaim:

1. A gas turbine plant'which comprises at least one compressor, at least one heater, at least one turbine, at least one cooler, and a recuperator interconnected by conduit means; said conduit means being constructed and arranged to pass cool gas from the cooler to the compressor, compressed gas from the compressor through the recuperator, from. the recuperator through the heater and into the turbine, from the turbine through the recuperator into the coolerand back to the compressor; shaft means for driving the compressor by the turbine, a second compressor -for passing compressedlmake-up gas to the cooler to mix with the compressed gas in the circuit, means for driving the second compressor by the turbine, said second compressor having a turbine stage ahead of and on the rotor thereof, a row of charged from the exhaust ,gas turbine.

stages is shortened in the same proportion as the volume of air is'reduced during compression.

When working with normal full-compressing can be reduced by opening the guide blading 26, so

that the expansion in the turbine stage is reduced until nally the pressure in space 34 is approximately the same as in space 33, In the limit case,

. when 'the compressing work is at a maximum, the

valve 35 is opened, so that the means'to be compressed bypass the turbine stage 23, 22 and reach the'space 34 direct from space 33 through the passage 33. l

The blading (Fig. 3) is shaped in suchy away that the best eillciency is obtained at normal load. With the maximum overload this emciency is reduced only by a slight extent in consequence 'of the Ventilating losses in the-turbine wheel, whilst at lower overloads and at part. loads there is also a slight fall of the elciency, since the somewhat altered velocities no longer correspond exactly to the forms of blading. y'

The invention can of course also beadopted for compressors when the initial pressure is less or greater than l atm. abs.

With the invention the advantage is .obtained that the quality delivered and the deliverypressure change simultaneously and nearly proportionally to Veach other with change of load.

high over a wide range..

2. lA gas turbine plant according to claim 1 which comprises a valve-controlled by-pass means operatively connectedto the second compressor for passing air around the adjustable guide blades and turbine runner blades to the impeller blades.

3. A gas turbine plant which comprises a rst compressor, a gas heater, a turbine, a cooler, conduit means leading working medium in a circuit through said compressor, said heater, said turbine, said cooler and back into-said iirst compressor, a

second compressor arranged to deliver working medium to that circuit to replace fluid discharged from it, coupling devices for transmitting work -between said turbine and said compressors, expansion turbine means arranged before said second compresso-r driven by the working medium supplied thereto, a coupling device for transmitting work between said expansion turbine means and. said second compressor, guide blading for said expansion turbine means in the intake thereto having adjustable` guide blades, a turbine for delivering useful, work outside Vthe plant, conduit means for delivring the iluid discharged from the circuit to the combustion chamber of the gas heater, conduit means for conducting the combustion gases of the gas heater to the turbine deliveringuseful wori, and means for discharging said combustion gas to the atmosphere after expansion in the turbine.

4. A plant according to claim 3 in which the 'coupling devices` for transmitting work between the first turbine and the compressors consist of direct drive shaft couplings, Y

5. A plant according to claim 3 having a, re,

cuperator in the circuit, one side of the heat transthe first compressor and delivering it to the heater,

the other side of saidheattransmitting surfacehaving conduit means for introducing working medium from the first turbine and delivering it to the cooler.

6. A plant according to claim 3 having conduit .means for delivering the working Ailuid compressed by the second compressor into the cooler oi'- the circuit.

5 '1. A plant according to claim 3 in which the expansion turbine means comprise at least one turbine stage, the second compressor comprises a rotor, and the couplingv device for transmitting work between said expansion turbine means and. 5 ,A said second compressor consists in mounting said turbine stage on said rotor'.

Y WALTER TRAUPEL.

` REFERENCES CITED The following references are of record in the tile of this patent:

FOREIGN PATENTS Number Country Date Italian Jan. 25, 1940 

